Loading and unloading mechanism for baking oven conveyers



Feb. 13, 1951 LOADING AND UNLOADING MECHANISM 7 Sheets-Sheet 1 Filed DSG. 17, 1945 Feb. 13, 1951 c. J. RUNDQUIST 2,541,386

` LOADING AND UNLOADING MECHANISM FOR BAKING OVEN CONVEYERS Filed Dec. 17, 1945 .7 Sheets-Sheet 2 Feb. 13, 1951 c. J. RUNDQUlsT LOADING AND UNLOADING MECHANISM FOR BAKING OVEN CONVEYERS 7 Sheets-Sheet 5 Filed DSC. 17, 1945 Feb. 1'3, 1951 c. J. RUNDQuls-r 2,541,386

LOADING AND UNLOADING MECHANISM FOR BAKING OVEN CONVEYERS Filed Dec. 17, 1945 '7 Sheets-Sheet 4 lFeb. 13, 1951 c .l RUNDQUIST 2,541,386

LOADING ND. UNLOADING MECHANISM FOR BAKING OVEN CONVEYERS Filed Dec. 17, 1945 7 Sheets-Sheet 5 venf.' @CUZ Junci'gualgi".

Bj @mm Feb. 13, 1951 c. J. RUNDQUlsT 2,541,386

LOADING AND UNLOADING MECHANISM FOR BAKING SVEN CONVEYERS Filed Dec. 17, 1945 fr sheets-sheet e /66 /66 /6 I //0 ,l 1 //2 l' /64/ /zzl/28 'l V i: l :N6 LJ 4 I//a i/0 yz l 33 /08- l IJ m1 Wifi-F3 I /zz H l x i 0@ /00 Inf/en for.'

Feb. 13, 1951 c. J. RuNDQUls-r LOADING AND UNLOADING MECHANISM FOR BAKING OVEN coNvEYERs 7 Sheets-Sheet` '7 Filed Deo. 17, 1945 Patented Feb. 13, 1951 LOADING UNLOADING MECHANISM FOR BAKING OVEN CONVEYERS Carl J. Rnndqnist, Chicago, 111/-, assigner to The Petersen Ovenv Company, Chicago, Ill., .a (zoppo-v ration of Illinois Application December 17, 1345 Serial No. 635,457'

1 3 Claims. 1

This invention relates tov commercial baking ovens, andV particularly to1 bakingv ovens of the type having a conveyorprovided with a plutality of spaced-apart tiltable trays.

Thisy invention is especially adaptable to ovens. in which the loading and dumping operations take place at the same end of the oven. Inl ovens. of this type the articles: to be baked obviously must. be carriedv in both directions .of travel, that is, on all runs of the conveyor, for removal therefrom adjacent the loading entrance.v The conveyortraysY carrying the articles to be bakedy must. be level at. all times, on allruns of the4 conveyor, and during their travel :around turns from one` toy anotherl There are av numberof advantages of this type of oven,` one being; compactness for saving off Space and materials of construction, and another being greater efficiency. for there is no idle run of the conveyor.A For example, if the articleswere inserted at one end and dumped at the. other, one runof the conveyor would of necessity return to the loading end empty., This "would Vmake the; oven twice as long; as it isv in the present construction,

obstacle encountered in. prior ovens oi this \general.I tyne was the lack of eifective means for dumping the trays near the point of loading;l and immediately renderV them; available for loading,

and a r.1.1ea ,;nsI for facilitating loading of the trays.

loading platform and pushed onto` a registered' `tray. The trays can thus be loaded while the conveyor is operating continuously.

The tilting means and the movable platform are arranged so that their operation coincidesl with the passingy of a tray adjacent to them, and the two. are synchronized to operate together, being driven bya single driving element, preferably, though not necessarily, by the conveyor chains;

The tray tilting means is designed so that the trays can be tilted to different angles to control they speed at which loads of diiferent Weights and/for sizes, may slide off of the trays.

The; movable loading platform registersv with the trays duringA an interval of travel thereo,

Vand disposed a short distance abovethemso as to, use. in.- connection with av continuously traveling conveyor.

The movable loading platform eliminates .the necessity,- of stopping the conveyor .to place each tray in registration with a platform forY loading, withv attendant overloading of theconveyor drive motor in startmg the conveyor atereaoh tray is. loaded as isnecessary in certain. ovens heretofore made. Another .d-ifcultv 0f IDI-im ovens having an intermittently operated .opnveyor is that even when the. Conveyor iS Stopped, the tray to. be loaded. .isy not yalways tesis-$113.- tion, with the. loading Shelf.A If the trayy stops above the loading shelf, it is dfclllt t@ slid@ 1711s? food containers onto-the tray and, may .neCQSir tate individufn handling of the pans. of, fioodstuii and, if the tray stops below the shelf,Y there is an. objectionable drop from, the Shelf. to the trail whichv may impair the quality, shape and. enpearance, of the baked food. stuft. 'lhe Inova-blc platter-moi my invention canl alsoy be used; as well wit-n intermittent drive, ii.. a, Stopping the: oon..- veyor to place each; tray in position. for loading, ii desired..

Another advantageous feature -is that; the mov,-

Aable loading platform sadaptable. to,` either lll/and or automatic loading.

Still another feature of the invention is that regardless. of the speed of the conveyor, the m0,- tion .of the movable loading platform is perfectly timed with the movement of the conveyor, and preferably, though not necessarily; the platform isA driven by the conveyor.

Anotheradvantage of the, invention resides in the fact that there are no speciali motorsy or `conveyor drives required for actuating the dumping mechanism and the movable loading platform.

With these andl other objects in view., my invention consists in the construction, arrangement and combination of the various parts of 'my device whereby the objects. contemplated are attained, as hereinafter more fully set forth, pointed-'out in the, claims, and illustrated in the accompanying drawings, wherein:

Figure 1 isa view of the oven as a Whole, partly in diagram and partly in section, and embodying; my invention.

'Figure 2: is a d-i-agrarnmaticy view in plan show;- ing the; relative positions.y ofY the principal oper# ating; devicesrand mechanisms. r

3 VFigure 3 is a plan view of a tray, and fragmentary portion of the conveyor chains.

Figure 4 is an enlarged section taken on line 4-4 of Figure 3.

Figure 5 is a view showing in full lines a tray with its grille in position of extreme tilt, and its normal position being shown in dot-and-dash lines.

Figure 6 is an enlarged sectional view taken on line 6-6 of Figure 3.

Figure '1 is an enlarged sectional view taken on line 1-1 of Figure 3.

Figure 8 is an end view of the drive mechanism and showing the oscillating cam for operating the movable loading platform in relative position therewith.

Figure 9 is a plan view of the drive mechanism and adjusting means for adjusting the height of the dumping cam.

Figure 10 is an enlarged sectional view taken on line |8|0 of Figure 9.

Figure 11 is a view taken on line of Figure 10.

Figure 12 is a layout gure of the movable 'platform and its operating linkage, parts in secltion, and showing the platform and linkage as viewed from approximately line |2-I2 of Fig- 'ure 2.

Figure 13 is a plan view of the linkage shown in Figure 12. Figure 151 is a view taken on line lll-I4 of Figure 9 and shows the oscillating cam for operating the linkage of Figures 12 and 13 which actuates the movable loading platform.

vure 1 shows a baking oven 20 of the type to which my invention is applied. This oven is of the continuously-operating type, having a continuously 4travelling conveyor upon which the pans of food stuff to be baked are placed. The oven is equipped with a blower unit shown at 22 for clearing the steam from the region at the front of the oven. The oven is broken away in the lower left-hand corner which is also at the front end of the oven, and shows a loading opening 23. A conveyor 24, a part of which is shown in dotfand-dash lines, extends horizontally in the bak- `ing chamber of the oven and doubles back for an additional run through the upper part of the vchamber of the oven toward the front end thereof, and back and then down to the lower part of the oven completing its cycle. In the portion vwhich is broken away, the relation of the conveyor to the loading entrance 23 is clearly shown. For the purposes of the present invention, the

lowermost run 25 of the conveyor will be regarded as travelling to the left, or toward the loading entrance 23 of the oven, and the upper run 26 '.travelling away from the loading entrance. .Trays 28 are secured to the conveyor 24 and pivoted thereon as will be explained later in connection with the dumping mechanism, and are spaced at regular intervals along the conveyor for proper operation in timed relation to the actuation of the dumping mechanism and movable loading platform. In order for the trays v28 to carry food effectively, they must be maintained level, and for this purpose the conveyor is made up of main chains 29 and 30 for supportl ing and carrying the trays 28, and an auxiliary chain 3| for stabilizing the trays and maintaining them level in the travel of the conveyor. The conveyor can be driven by a conventional continuous drive operating through gear 32. For a full description of this general type of conveyor, reference may be had to Patent No. 2,242,813, issued May 20, 1941, to John V. Cook.

Referring to Figure 2, which is a diagrammatic view in plan of a portion of the oven, the relative positions of the principal operating parts of my invention may be observed. The source of power for the synchronized dumping mechanism and movable loading platform resides in two sprockets 34 and 36 secured to a shaft 38 for rotation therewith by keys 39. The shaft 38 is rotatably mounted in the oven frame40. The sprockets and shaft are driven by the conveyor 24. The sprocket 34 is driven by the main chain 29 on one side of the oven, and the sprocket 36 is driven by the auxiliary chain 3| on the opposite side of the oven. On the outer end of the shaft 38 on the side of the oven next to the main chain 29 and mounted for clutching engagement with the shaft 38, is a gear 42 which meshes with another gear 44 xedly secured on a shaft 46. Shaft 38 is mounted for rotation in the oven frame 40 by suitable bearings, and shaft 46 is mounted for adjustment on the frame 40 by a special device, the features of which will be hereinafter described.

As shown in Figure 3, the tray 28 travels in the direction indicated by the arrow 48 on the lower run 25 of the conveyor 24. The tray is supported by trunnions 58 and 5l disposed near the leading edge of the tray, and connected to and supported by the main chains 23 and 30, respectively. Trunnions 50 and 5| are formed on the extremities of a transverse shaft 52, about which the grille of the tray 28 is adapted to tilt. Between the auxiliary chain 3| and the main chain 3U next to it, is disposed a stabilizing arm 53 for each tray, each of which is nxedly secured to the trunnion 5| of an aligned tray. On the outer end of the stabilizing arm 53 is another trunnion 54 extending in the opposite direction from trunnion 5|, and pivotally mounted in the auxiliary chain 3|.

Referring to Figures 3 and 5, the tray 28 is made up of a grille 56 and supports 51 therefor. The tray supports 51 are rigidly supported by the transverse shaft 52, for example, by welding them to sleeve 58 which, with stub shafts 58', make up transverse shaft 52. The stabilizing arm 53 being also rigid with the shaft 52, the tray supports 51 are maintained in substantially a horizontal position because of the fact that the two ends of the stabilizing arm 53 are maintained horizontal by the constant relative positionsA of main chain 30 and auxiliary chain 3|.

The tray grille 56 is supported at two points by the transverse shaft 52 by slots 56 formed in' the side panels of the grille and which fit'over the shaft 52 beyond the ends of the sleeve 58. The grille is held in place thereon by yoke member 51 tted on the underside of the transverse shaft 52 and closing the open ends of the slots 56. The grille is therefore supported at four points, two on the transverse shaft 52 and two at the rear end of the tray on the supports 51.

The normal position of the tray grille 56 is shown in dot-and-dash outline, and when it is in this position, thek trailing edge rests upon the supports 51. Secured to the underside of the tray grille 56 are cam shoes 59,:each having a forward inclined surface 6U and a rearward inclined sur.- face 6|. One such. cam shoe 59 is `located at each end of the -traygrille 5B. for engagement `with .dumping cams 62 mounted on .the shaft 46. The dumping cams 62 are secured to the shaft 46 by keys 63, or other similar means.

Referring to Figures 6 and 7, the conveyor 2.4 in travelling in the direction of the arrow .64, engages theY two. sprocket wheels 34 and 36. The

4sprocket wheels 34 and 36 each have one tooth partially cut away, as indicated at 65 and ,68,

respectively, tov prevent interference of the vsprocket 34 with the trunnion 50. of the tray 28 supported in the main .chain 29, and the sprocket 3.6 from interfering with the trunnion 54 on the stabilizing arm 53 which is secured in the aux- Viliary chain 3|. It will be noted that. these two "sprockets 34 and .3.6 are angularly positioned relatively to each other as may be seen in Figure` 6., so that the cutout portions 6.6 and 68 are not in register, and because they are not in register, there is no likelihood of either of the chains 29 and 3| skipping over the teeth on. their sprocket 'because at least one of the sprockets 34 and 3.6 vwill be positively engaged by its respective chain at all times, thus insuring continuous driving of shaft 38 incident to movement of the conveyor.

The sprocket 34 is shown in dot-dash lines in Figure 6, since it would not actually be seen in this view, because it is located on the opposite Vside of the oven; but it is superimposed on this figure to show its relative angular position with 'the sprocket 36.

When the trunnion 5|) is in engagement with the cutout portion 66 of sprocket 36, the trun-nion 54 is disposed rearward of this point, and accordingly the cutout portion 68 is angularly disposed so as to engage the trunnion 54 when the auxiliary chain has moved forwardly an amount corresponding to the distance between trunnions 5|] and 54. It will also be seen that the full teeth -of the sprockets 34 and 36 are not in register, be-

cause the distance between the trunnion 50 and the trunnion 54 is not a whole multiplel of the olis-n tance between the rollers on the chain. By thus having the sprocket 34 engaged by the main chain 29 and the sprocket 36 engaged by the auxiliary chain 3|, there is positiveV drive through i Ythese sprockets to the shaft 38 at all times.

The conveyor 24 travelling in the direction of the arrow 64 (see Fig. 6) rotates the sprockets 34 and 36 and shaft 38 in counterclockwise direction, as seen in Figure 8, and the gear .42 being secured to the shaft 38, also rotates counterclockwise. The gear 44 (see Figures 6 and 8) is in constant mesh with the gear 42 and is rotated .clockwise thereby. The gear 44 being secured to the shaft 46, rotates the shaft and .dumping cams 62 clockwise also. When the tray 28 is travelling forward, the dumping cams 62 are rotating clock wise (see Figure 5), and when the tray reaches a predetermined position, the dumping cams 62 engage the leading surfaces 60 of the cam shoes .59, thereby causing tilting of the tray grille 56 to the position shown in full lines in Figure 5. The dumping mechanism, including the dumping cams 62, is positioned at such a point near the forward end of the oven. that the tray grille 65 is fully tilted to permit the load l2, in the form of pans of food stuff, as indicatedl in. Figure l, to slide off thetray onto a cross conveyor i4, which carries the baked products out of the side of the oven. The cross conveyor 14 may be of any desired construction and does not form a part of this invention, which conveyor '14', it may be un- E derstood, is. intermittently operated, its opera-4 tion being. arrested' during the dumping of the trays 28. After the tray- 28 is tiltedl and the load slides off, continued travelling of the conveyor and movement of the dumping cams 62 causes the cams 62 to engage trailing cam surfaces 6| of the cam shoes and thus causing the grille 56 to return to its normal position under its own weight. The tray grille being pivoted near its leading edge, the preponderance of weight rearward of the leading vedge causes it to descend by gravity under control of cam shoe 59 and dumzpe ing carns 62.

It is desirable to be able to. adjust the degreev of tilt for the tray grilles 56, to provide for a uniform rate at which the food containers will slide off the tray onto the cross. conveyor 14, since loads of' different weights and/or sizesl will slide off at diiferent rates of speed. To accomplish this, I have .devised a novel method of adjusting the height. of the dumping cams 62 so that they will engage the trays 28 to different extents.

Attention is directed to Figures 8, 9, l0 and l1 for this novel mechanism for adjusting they dumping cams 62. A vertically disposed plat e 16 is secured to the oven flamey 4.3 as by welding as indicated at 18 (see Figure 10), and is provided with an opening at one end for receiving shaft y38 and its bearing housing 86, and at the other end with a slot 32 for receiving shaft 45 and its bearing housing 34. The slot 82 is curved about an arc whose center of curvature is the axis of thek shaft 38. Mounted on the forward side of the plate i6 (as Viewed in Figures 9 and l1)v is another vertically disposed plate 86 held in contact with the plate 16 by means: of bolts 8B secured to the plate '16. Bolts 88 t in 4slots 9] formed in the plate 86, and these slots also are curved about arcs having their center of curvature at the axis of shaft 38'. Openings are formed in either end of the plate 86 for receiving shaft 38 and its bearing housing 83, and shaft 36 and its bearing housing 8.4. The housings 8.@ and 64 are welded to the plate 86 as indicated at 92. An additional plate Q4' horizontally disposed and positioned perpendicularv to the plate 86 is welded theretoand to the housings. 86 and 84 as indicated at 96. A lug 93 is welded to the housing 84 at the side thereof farthest from shaft 33, and is provided with an opening for the reception of an eye bolt |613 secured at |552 on the oven frame. The end' of the eye bolt itl) is threaded and provided with nuts |04 above and below the lug 98. The left end o-f the plate 86 as viewed in Figure 11 can be raised or lowered, rotating about shaft 38 as a pivot. This is accomplished by adjusting the nuts ttf! on the eye bolt till). When the plate 86 is raised or lowered, it carries the shaft 4@ with it. The curvature of slot 82 permits the housing 34 to ride therein and the curvature ofthe slots 9) accommodate the relative -movement of the bolts 88 in the rotating movement of the plate 86:. When it is desired to decrease the extent to which the tray grilles 5.6 will be tilted, the left end of the plate 86 is lowered carrying with it the housing 84A and shaft 46. The dumping cams .62

'being mounted on the shaft 46 are lowered also,

and, accordingly, do not have such a great cam- `ming effect on the cam shoes of the tray grilles 56, tilting the trays a lesser amount than when the plate 36 is in its uppermost position, or as shown in the drawings. Similar adjusting means is provided at the opposite side of the oven for supporting the other ends of the shafts 38 and 46; -The adjusting device is precisely the same ving end of the arm |46.

as the one just described, exceptl that it is opposite and symmetrical, and a description of the present will suffice for both.

In order to disconnect the dumping mechanism, I provide clutch means for declutching the gear 42 from the shaft 38, and thereby disengage the drive to gear 44. The hub |06 of the gear 42 is mounted on the shaft 38 for rotation with respect therewith and is secured on the shaft by a collar |08. Mounted in the web I of the gear 42 is a spring-pressed plunger H2 sliding in a sleeve H4 in the gear 42 and a sleeve H6 which is disposed near thevouter periphery of a clutch disc H8. Clutch disc H8 is welded to a hub |22 which, in turn, is secured to the shaft 38 for rota- Y tion therewith by a key |20. When it is desired to disconnect the gear 42, the plunger H2 is Withdrawn from the sleeve H6 in the clutch disc H8 against the action of the spring |24 and it may be locked in that position by a pin |26 which passes through the plunger H2, which ts in slot |28.

In connection with the dumping mechanism as described, I have provided a movable loading platform which is operated in timed relation to ythe loading entrance of the oven, a loading platform |30 is disposed in said entrance and moves vertically with the trays for a short distance. The food containers 12 which are placed on the movable platform can easily be pushed onto the registering trays during the time interval that the movable platform moves with the trays. The platform then lowers to be in position for cooperative movement with the next successive tray.

The movable platform |30 (see Figures l, 12 and 13) is pivoted on trunnions |32, positioned at either end of the platform and mounted in the oven frame 40. On the under surface of the movable platform are provided wear strips |34 on which rollers |36 are adapted to have contact.

The rollers |36 are mounted on the swinging ends of arms |38 which are fixedly secured to a horizontally extending rock shaft |40, mounted in housings |42 at either end of the shaft |40. The housings are supported by plates |44 secured to the oven frame 40. An arm |46 is fixedly secured to one end of the shaft |40 for rocking it.

I provide a multiple linkage for oscillating the movable platform |30. This linkage is indicated in its entirety by the numeral |41, and includes a toggle link |48, pivotally secured to the swing'- The other end of the toggle link |48 is pivotally secured to a lever |50 which is pivoted at |52 on a bracket |54, iixedly mounted on the oven frame 40. The left-hand arm of the lever |50, or that nearest the toggle link |48, extends through a yoke |56` for sliding vand guided movement therein, the yoke |56 being secured to a bracket |58 which is also mounted on the oven frame. On the opposite end of the lever |50 a second toggle link |60 is pivoted, and this toggle link |60 is also pivoted to a second lever |62 which is pivoted at |63 on bracket |64 xedly mounted on the oven frame. On the end of the lever |62 opposite toggle link |60, is a roller A|66 mounted in a bracket |68 secured to the lever |62. The roller |66 is adapted for engagement .-by anV oscillating cam |69. While the cam |69 itself does not oscillate, it is referred to as an oscillating cam because its function is to produce an oscillating motion to the movable platform |30.

The oscillating cam |69 is secured to the clutch disc H8 by bolts |12 extending through slots |14 in the cam |69, and threaded into the clutch disc H8. Lock screws |16 (see Figures 14 and 15), extend through openings in the lugs |18 welded to the cam |69, and threaded into the clutch disc ||8. The cam |69 has limited adjustment on the clutch disc H8. Initially the lock screws are not in place as shown. The cam |69 is adjusted as need be on the bolts |12 for proper timing. The bolts |12 are then tightened, the mechanism is operated to test the timing, and when the proper timing is found, holes are tapped and threaded in the clutch disc H8, and lock screws |16 are tightened in place to secure the cam |69, xedly to the clutch disc H8.

The cam |69 is therefore secured for positive rotation with the clutch disc H8. As the clutch disc H8 and the oscillating cam |69 are rotated, the roller |66 is engaged by the cam |60, for operating the linkage described in Figures l2 and 13 for oscillating the movable platform |30. As viewed in Figure l2, the clutch disc H8 and the oscillating cam |69 rotate counterclockwise. The cam in the position shown in this figure is in engagement with the roller |66 and is about to operate the linkage. As the cam |69 rotates to the left, the roller |66 and the right-hand end of the lever |62 are raised to the position shown in dotted lines, drawing downwardly the toggle link and the right-hand end of the lever |50. As the left-hand end of the lever |50 is thereby raised, it draws upwardly the toggle link |48 and rocks the arm |46 and shaft |40 counterclockwise, which rocks the arms |38 in a counterclockwise direction also, causing their rollers |36 to move over the wear strips |34, and thereby moving the movable platform |39 to the position shown in dotted lines. On continued rotation of the cam |69, the roller |66 riding over the hump and down the opposite side of the cam, permits the linkage to return to the full line position under the weight of the movable platform |36, which returns to the full line position shown. The lower limit of vthe movable platform |30 is determined by the yoke |56 which serves as a stop for the left-end of the lever |50 for arresting the linkage in the position shown in full lines and thereby preventing the movable platform I3!)l from lowering any farther. R0.- tation of the oscillating cam |69 thus imparts an oscillating motion to the movable loading platform |36, and its range is that shown in'- the full and dot-and-dash line positions in Figure l2.

Referring now to Figure 16, the relative position of the movable platform |30 and trays 28 are shown. As the leading edge of each tray 28 approaches the free edge |3| of the movable loading platform, the latter is resting in its lower;- most position. The oscillating cam |69 is so timed with respect to the conveyor 24, being driven by the chains thereof, that just before the tray reaches the level of the movable loading platform |30, the cam |69 commences to raise the platform, which continues to be raised and lead the tray until the upper limit of movement of the platform is reached. The free edge |3I "of the movable platform |30 is adjacent to the lead-- ing edge of each tray 28 successively, as it moves upwardly past the loading entrance 23 of the oven, and when the successive trays register therewith, said free edge is normally positioned slightly above the griliev supporting surface of; the tray andmaintains suchrelationto the trays,

throughout the raising movement of the platform. The purpose of this displacement is to permit foodl containerson the movable platform |30 to vbe easily pushed onto'the tray 28. In practice this displacement is approximately onequarter inch but this of `course may vary to suit different conditions. The period of travel from the full line positions to the dotted line posi.- tions is sufficient time in which to push all of the foodv containers from the movable platform |30` onto the tray 23. Past this point, the tray continues upwardly as the conveyor continues to travel, and the movable platform returns to its lower position and remains temporarily at such position until the oscillating cam lS makes. another revolution and operates the linkage.

This loading platform is adapted for either automatic loading or hand loading. It can also be. used for intermittent conveyor travel as well as for continuous travel, for whatever point a tray may stop in approximate alignment with loading entrance where it can be loaded, the.

movable platform. will always, be .positioned av slight distance above it and in registration therewith. The device can therefore be applied to nearly all ovens, eliminating thev necessity for special drives and timing apparatus.

It is to be noted that by virtue of the construction described, the linkage and the movable platform 113.0 are actuated in correlation to the conveyor 24, so that as the conveyor travels and each successive tray aligns with the loading entrance, the platform is then moved `in registered relation to the Itray as above described.

When a pivoted arm rotates (consider the movable platform i3d a pivoted arm for the moment), its rate of vertical movement varies constantly. If the movable platform |39 were to rotate, that is, be raised,y in a uniform circular motion, the displacement between the free edge [3l of the movable platform i3!) and thev trays 28 would not be the same in the llower positionv as in a higher position. iThe particular shape of cam |69 overcomes this condition.

. Referring to Figure 14, it will be seen that the curvature of .the camming surfaces HD and |`H of the oscillating cam 169 is not uniform. The lower portion of the cam is relatively wide, tapering abruptly at a point farther out, and then assuming a new curvature. The exact form of this curvature of the surfaces VIE! and l 1I need not be described in detail, but suffice it to say `that due to its peculiar shape., the linkage is operatedv at a rate rso that the free edge I3! of the .movable platform |3 is caused to remain in proper correlation to the tray throughout the range of vertical movement of said free edge of the platform.

There is ,positive synchronization between the dumping mechanism and loading mechanism. There is only one position in which the clutch disc H8 can be locked in kposition with the gear 4'2.. When the clutch disc II8 is in clutched relation With the gear 42., the oscillating cam |69 will always be in the same position relative to the .dumping cam 6.2, .thereby tilting the trays .2 8v and oscillating the movable platform 1.3.0. in proper timed relation to the travel .of the conveyor.

Although I have herein shown and described a preferred embodiment of my invention, manifestly it is .susceptible of modifications and rearrangement of .parts without departing from the spirit and scope thereof. I do not, therefore, Wish to be understoodas limiting this invention to the. y precise form herein disclosed, except as I may be ...3.

so limited by the appended claims.

I claim is my invention:

pivot. means secured to the chains, comprising, in

combination, tilting means for tilting the trays. at a given point along their path of travel, a movable. i. loading platform mounted adjacent the loading entrance and having one edge disposed adjacent the path of movement of the trays, oscillating means for moving the movable loading platform through a limited range and causing said one `edge to be moved in the direction of movement of the trays and at substantially the same level of each tray successively, means for driving the tilting means and the oscillating means in .syn-

chronism, and means operated by the conveyor chains for driving the synchronizing means.

2. A synchronized dumping and loading mechanismA fora baking oven comprising a conveyor having a portion adapted to travel upwardly adjacent the loading entrance of the oven, and means for driving the conveyor, the conveyor having drive chains and a series` of trays spaced; along the conveyorrand adapted to be tilted aboutl pivot means secured to the chains, comprising .in combination, tilting means for tilting the trays at a given point along their path of travel, a movable loading platform pivoted adjacent the loading entrance and having its free end disposed.

adjacent the path of travel of the trays as they pass the loading entrance of the oven, oscillating.r means for oscillating the movable platform-f through. a limited range, theV .free end of the movable platform being substantially at the levelof a tray lduring the travel of said free end of the movable platform through its range in one direction, means for driving the tilting means and the".- oscillating means in synchronism, and meansop-f erated by the conveyor chains for driving the synchronizing means.

3. A synchronized dumping and loading mechanism for a baking oven comprising a conveyor having a portion adapted to travel upwardly adjacent the loading entrance of the oven, and means for driving the conveyor, the conveyor having drive chains and a series of trays spaced along the conveyor and .adapted to be tilted about pivot means secured to the chains, comprising in combination, tilting means for tilting the trays at a given point along their path of travel, said tilting means being adjustable for varying the degree of tilt of the trays, a movable platform pivoted adjacent the loading entrance and having its free end disposed adjacent the trays as they pass the entrance of the oven, oscillating means for oscillating the movable platform through .a

conveyor in spaced relation therealong, compris;

ing, in combination, cam shoes on the trays, and Y for` successively tilting the trays, the movable dumping cams being elevated continuously during the entire tilting operation of the tray while thetray is in position for dumping, means operated bythe conveyor for elevating the dumping cams, and clutching means for disconnecting saidlmeans from thel conveyor, said clutching means being connectible with said conveyor so as to cause elevation of said dumping cams in timed synchronism with the spacing of said trays.

v5.7 In a barking oven comprising a conveyor having a portion adapted to travel vertically adjacent the loading entrance of the oven, and means for drivingthe conveyor, the conveyor having a series of spaced trays, the combination of a platform pivoted for vertical swinging adjacent the loading entrance, an arm pivoted for vertical swinging below the platform, the pivoted arm having a roller on its free end for contacting the under side of the platform, linkage means for oscillating the pivoted arm and thereby the platform, and cam means driven in timed relation to the conveyor for operating the linkage.

6*'. Dumping mechanism for a baking oven comprising, in combination, a traveling conveyor, the conveyor having driving chains and a series oftrayssecured to the chains in spaced relation, the trays being pivoted for tilting movement, cam means secured on said trays, shaft and gear means actuated by said conveyor, second shaft and gear means meshing therewith andv driven thereby, dumping cam means on said second shaft, said dumping cam means being adapted to successively engagethe cam means on said trays for tilting the trays, said second shaft and gear means being adjustable in an arc around the axis of said first shaft and gear means.

7. Dumping mechanism for a baking oven having a traveling conveyor, said conveyor having a horizontal run, a series of trays pivoted on the conveyor in spaced relation therealong, comprising, in combination, cam shoes on the trays, shaft and gear means actuated by said conveyor, second shaft and gear means meshing therewith and driven thereby, both said shaft and gear means` being positioned below said horizontal run, dumping cam means on said second shaft, said dumping cam means being adapted to successively eri-i` gage. the cam means on said trays for tilting the trays, said second shaft and gear means being adjustable vertically in an arc around the axis of said first shaft and gear means.

8. Ina baking oven comprising a conveyor having a portion adapted to travel vertically in an arcuate path adjacent the loading entrance of the oven, and means for driving the conveyor, the conveyor having a series of spaced, tiltable trays, thecombination comprising rotatable dumping cam means operable for tilting said trays at a predetermined point in the path of movement of the trays, a movable platform mounted adjacent the loading entrance and having one edge disposed adjacent the path of movement of the trays, rotatable cam means for oscillatably moving the movable platform through a llimited range in the direction of movement of the trays and at substantially the same level of each tray successively, and means operated by said conveyor for rotating said cam means.

9. In a baking oven comprising a conveyor 12 having a portion adapted to travel vertically in an arcuate path adjacent the loading entrance of the oven, and means for driving the conveyor, the conveyor having a series of spaced, tiltable trays, the combination comprising rotatable dumping cam means operable for tilting said trays at a v predetermined point in the path of movement of the trays, a movable platform mounted adjacent the loading entrance and having one edge disposed adjacent the path of movement of the`v trays, rotatable cam means for oscillatably moving the movable platform through a limited range in the direction of movement of the trays and at substantially the same level of each tray sucl an arcuate path adjacent the loading entrancel of the oven, and means for driving the conveyor,

the conveyor having'a series of spaced, tiltableA trays, the combination comprising rotatable dumping cam means operable for tilting said trays at a predetermined point in the path of movement of the trays, a movable platform.

mounted adjacent the loading entrance and having one edge disposed adjacent the path of movement of the trays, rotatable cam means for oscillatably moving the movable platform through a limited range in the direction of movement of the trays and at substantially the same level of each tray successively, means operated by said conveyor for rotating said cam means, and clutch means for disconnecting said dumping cam means from operation by said conveyor, said clutch means being operable for connection of said dumping cam means for operation by said conveyor in single predetermined, fixed, timed relationship with said second cam means.

l1. Dumping mechanism for a baking oven, comprising, in combination, a continuously traveling conveyor, the conveyor having driving chains and a series of trays secured to the chains in spaced relation, the trays being pivoted for tilting movement, cam means secured on said trays, rotatable cam means adapted to engage the cam means on the trays for tilting the trays successively at a given point in their line of travel, and driving means operated by said conveyor for rotating said rotatable cam means, said rotatable cam means being in engagement with the cam means on a tray during a portion of its cycle of rotation, said cam means being bodily movable toward and from the trays for varying the degree of tilt of the trays, said rotatable cam means, in all positions of bodily movement thereof, being in driven relationship to said driving means.

' l2. For use with an oven having a loading entrance, and a conveyor adapted to travel in anV arcuate path past the loading entrance, the combination comprising a platform pivoted adjacent the loading entrance on a horizontal axis for vertical swinging, a pivoted arm for oscillatably swinging the platform, linkage for operating the pivoted arm, a rotatable element driven by the conveyor, cam means mounted on said rotatable element, said cam means being operative for operating said linkage and thereby raising the free edge of said platform in timed relationship with said trays successively, said cam'means having a limited range of adjustment circumferentially of said rotatable element for producing registered relationship between said platform and trays in the upward swinging movement ofthe platform.

13. In a baking oven comprising a conveyor having a portion adapted to travel vertically in an arcuate path adjacent the loading entrance of the oven, and means for driving the conveyor, the conveyor having a series of spaced, tiltable trays, the combination comprising rotatable dumping cam means operable for tilting said trays at a predetermined point in the path oi movement of the trays, driving means operated by said conveyor for rotating said cam means, said cam means being in engagement with a tray during a portion of its cycle of rotation, said cam means being bodily movable toward and from the trays for varying the degree of tilt of the trays, said rotatable cam means, in all positions of bodily movement thereof, being in driven relationship to said driving means, armovable platform mounted adjacent the loading entrance and having one edge disposed adjacent the path of movement of the trays, a rotatable element driven by the conveyor, second cam means mounted on said rotatable element, said second cam means being operative for oscillatablymov- 14 ing the movable platform through a limited range in the direction of movement of the trays and at substantially the same level of each" tray successively, means operated by the conveyor for rotating said element, said second cam means having a limited range of adjustment circumferentially of said rotatable element for producing registered relationship between said platform and trays during raising movement of said platform.

CARL J. RUNDQUIST.

REFERENCES CITED The following references are of `record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,048,834 Hunt Dec. 31, 1912 1,312,294 Allison Aug. 5, 1919 1,766,142 Olson June 24, 1930 2,002,009 Hart et al May 21, 1935 2,342,393 Feige Feb. 22, '1944 2,397,726 Cook Apr. 2, 1946 

